History, Credits, License, Citing

History and Credits

Version 1 (released 1995, Macintosh only) was written by David Brainard, with some help from others and support from an NSF ILI grant awarded to David Brainard. Version 2 (released 1996 for Macintosh and 2000 for Windows) was written by David Brainard and Denis Pelli, incorporating Denis Pelli’s VideoToolbox, with help from others. In particular, Mei Zhang, Elliot Waldron and Allen Ingling contributed heavily to the first working version for Windows. Version 2.5 for Windows and initial development of the OpenGL Version (now called Version 3) were Allen Ingling’s work, supported by core grant NEI P30 EY013079. Mario Kleiner then made extensive improvements to bring Version 3 to its current state. Richard Murray contributed the direct interface to OpenGL calls (MOGL). Tobias Wolf contributed the automatic documentation generator that generates our online function reference.

Version 3 is under active development.


Most parts of the Psychtoolbox-3 distribution and its source code are freely redistributable under a OSI approved open-source license. Most material is covered by the MIT license or a MIT compatible license. A few internal libraries and components are covered by other free software licenses which we understand to be compatible with the MIT license in the way we use these, or they are in the public domain. By distributing the complete source code for Psychtoolbox-3 under these terms, we guarantee that you and all other users will have the freedom to redistribute and change Psychtoolbox. The exact license text of Psychtoolbox is included as the file License.txt in the root folder of any Psychtoolbox-3 installation. A few non-essential files stored in the PsychContributed subfolder are neither free software nor open source software, but redistributable by permission of their respective authors.

Please don’t thank us. Cite us.

You’ll be joining a distinguished group of authors and grantees.

If you want to acknowledge use of this software when you publish your research, you might say something like this,

“We wrote our experiments in Matlab, using the Psychophysics Toolbox extensions (Brainard, 1997; Pelli, 1997; Kleiner et al, 2007).”

  • Brainard, D. H. (1997) The Psychophysics Toolbox, Spatial Vision 10:433-436. [PDF]
  • Pelli, D. G. (1997) The VideoToolbox software for visual psychophysics: Transforming numbers into movies, Spatial Vision 10:437-442. [PDF]
  • Kleiner M, Brainard D, Pelli D, 2007, “What’s new in Psychtoolbox-3?” Perception 36 ECVP Abstract Supplement. [HTML]

We’re happy and grateful to find that more and more users are now citing their use of this software. Getting this credit helps us justify the time we continue to devote to developing and maintaining this free software for use by the entire vision community.

Although these papers were written in reference to Version 2 of the toolbox, they remain the best current citation. Once the software stabilizes a bit more, we hope to write a short note describing the design and implementation of Version 3 so that appropriate credit may be given to those who made substantial contributions to PTB-3.

for users of the EyelinkToolbox .